CN1454799A

CN1454799A - System and method for controlling start and following acceleration course of automobile

Info

Publication number: CN1454799A
Application number: CN03149154A
Authority: CN
Inventors: 門田圭司; 清水弘一; 鈴木英俊
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2002-05-02
Filing date: 2003-04-29
Publication date: 2003-11-12
Anticipated expiration: 2023-04-29
Also published as: KR100499593B1; JP3539422B2; EP1359041A3; EP1359041A2; JP2003320859A; EP1359041B1; US6898505B2; KR20030086421A; US20040030480A1; CN100408369C; DE60328329D1

Abstract

A system is provided, which controls a starting and the subsequent vehicle acceleration procedure of a motor vehicle. The system compares a predetermined variable that grows continuously during the starting procedure to a threshold value. It determines a first desired value of torque in response to operator demand, and a second desired value torque in response to acceleration slip. The system performs a feed-forward 4WD control in response to the first desired value of torque when the predetermined variable is lower than or equal to the threshold value. The system determines whether or not driving situation justifies a change from performing the feed-forward 4WD control to performing a feed-back 2/4WD control in response to the second desired value of torque.

Description

Control starts and the system and method for car acceleration process subsequently

Technical field

The present invention relates to be used for that the controlling machine motor vehicle starts and the system and method for accelerator subsequently.

Background technology

In Japanese documentation JP-A 08-207605, disclosed the automobile (power actuated vehicle) that under 4 wheel drive (4WD) or 2 wheel drive (2WD) pattern, to operate.Automobile can start at the 4WD mode state.Transmitting device has the torque distribution power-transfer clutch.The responsive control signal adjustment is applied to the hydraulic pressure of power-transfer clutch, can change the size of the moment of torsion of telling of engine output torque.Controller produces control signal.Controller uses accelerator pedal depression and vehicle wheel rotational speed as input.Controller calculates according to vehicle wheel rotational speed and quickens to slide.Controller calculates first torque value according to accelerator pedal depression, calculates second torque value according to quickening to slide.Controller is set up automobile threshold velocity (for example 20km/h), and the speed of a motor vehicle and automobile threshold velocity are compared.When the speed of a motor vehicle was lower than the automobile threshold velocity, it was basic moment of torsion that controller is provided with numerical value bigger in first numerical value and the second value.When the speed of a motor vehicle was equal to or higher than the automobile threshold velocity, it was basic moment of torsion that controller is provided with second value.Controller determining to consider car deceleration in the control signal according to basic moment of torsion, so that power-transfer clutch transfer of torque ability descends fast, thereby forbids 4WD rapidly.This measure prevents emergency braking effectively.

In the startup of known system and car acceleration process subsequently, because always life period postpones, so forbid the 4WD pattern when the speed of a motor vehicle reaches the automobile threshold velocity, this just causes that acceleration takes place slides, and is allowed to up to another 4WD pattern.The disadvantage of this process is, only relies on the control of automobile threshold velocity to quicken to slide when conversion, so the automobile threshold velocity descends and can not be lower than a certain lower bound, also is like this even need to improve the situation of fuel economy.

Summary of the invention

The purpose of this invention is to provide the system and method that is used for Control of Automobile startup and accelerator subsequently, thereby make automobile between the starting period, have outstanding fuel economy and best acceleration capability.

According to an example embodiment of the present invention, apply moment of torsion with all-wheel drive mode activated automobile by response command to wheel, be provided for the Control of Automobile startup and reach the method or the system of accelerator subsequently, this method or system comprise:

Starting and subsequently during the accelerator of automobile, predetermined variable and the threshold value that increases continuously compared;

The response driver requires to determine first expectation value of moment of torsion;

Second expectation value that moment of torsion is determined in slip is quickened in response;

When predetermined variable was less than or equal to threshold value, first expectation value of response moment of torsion was determined order; With

Determine whether the driving situation should determine that order changes to the definite order of second expectation value of response moment of torsion from first expectation value of response moment of torsion.

The accompanying drawing summary

Description by reference the following drawings is done will have one to be expressly understood to the present invention.

Fig. 1 is a simplified diagram of having implemented automobile of the present invention.

Fig. 2 is the diagram of circuit of expression engine controller work.

Fig. 3 is the diagram of circuit of expression pull-in control system (TCS) controller work.

Fig. 4 is the hardware chart that is illustrated in interrelation between all-wheel drive or 4WD controller, engine controller and the relevant device.

Fig. 5 is the block scheme of 4WD controller.

Fig. 6 is a diagram of circuit, and expression is according to the work of an embodiment of system of the present invention or method, and this system or method are used to control and start and the accelerator of automobile subsequently.

Fig. 7 is a diagram of circuit, and expression is used for realizing with software the control program of expectation load torque clipper parts.

Fig. 8 is a diagram of circuit, and expression is used for realizing with software the control program of expectation load torque clipper parts.

Fig. 9 A is the diagram of curves of expression work embodiment illustrated in fig. 6 to 9E.

Figure 10 is a diagram of circuit, and expression is according to the work of another embodiment of system of the present invention or method, and this system or method are used to control and start and the accelerator of automobile subsequently.

Figure 11 is a diagram of circuit, and expression is according to the work of the another embodiment of system of the present invention or method, and this system or method are used to control and start and the accelerator of automobile subsequently.

Figure 12 is a diagram of circuit, and expression is according to the work of another embodiment of system of the present invention or method, and this system or method are used for the start-up course of Control of Automobile.

The specific embodiment

Description, automobile shown in Figure 1 has been implemented according to vehicle power control system of the present invention.This automobile comprises one or first power system, and another or second power system.First power system comprises the primary mover of explosive motor 2 forms.First power system drives with first group of

wheel

1L and 1R and connects.Second power system comprises the electric traction electrical motor 4 as the driving torque source, also is included between electrical motor 4 and second group of wheel 3L and the 3R power-transfer clutch 12 as torque transmission.

In described automobile, driving engine 2 is main sources of driving torque.Driving engine 2 has the air inlet pipe with inlet manifold 14 forms.In inlet manifold 14, driving engine 2 has main throttle 15 and sub-throttle gate 16.

With shown in the form response speed-up command of acceleration pedal of automobile, main throttle 15 is opened with respective degrees, this speed-up command is the order of accelerator pedal depression (APO) form of accelerator 17.In described automobile, APO can be with the expression of the percentum (%) of angle, this angle is the vehicle drive person handles accelerator 17 from the releasing position to all depressing angulation.Being operatively connected between accelerator 17 and main throttle 15 can be that mechanical connection is as directed by whole backguys or actuator system realization.Actuator system comprises acceleration sensor 60, engine controller 18 and unshowned throttle actuator.Engine controller 18 monitoring acceleration sensors 60 are determined the expectation value of main throttle 15 open angles, and are calculated actuator commands to receive the APO of accelerator 17.The order of responsive actuation device, throttle actuator is adjusted to desired value with main throttle 15.

For sub-throttle gate 16 is activated, provide stepper motor 19 and throttle sensor 62.The Step-motor Control device of pull-in control system (TCS) controller 20 receives the control signal of representing with angle delta θ.Definite mode of this angle delta θ will be described with reference to diagram of circuit 2 and 3 afterwards.The step number that TCS controller 20 calculated step electrical motors 19 rotate.Step-motor Control device 20 receives the output of throttle sensor 62 to form the closed loop control of sub-throttle gate 16.Owing to use sub-throttle gate 16, make the output torque Te of driving engine not rely on main throttle 15 present positions and change independently.

Be transmission engine torque Te, first power system further comprises change-speed box (transmission system) 30 and diff 31.Change-speed box 30 has different gear bands.In described embodiment, change-speed box 30 is the automatic transmission with hydraulic torque converters that comprise torque converter.Torque converter comprises pump impeller, stator and turbine.The bent axle of pump impeller and driving engine 2 links with its rotation.The input shaft of turbine and automatic transmission with hydraulic torque converter links.The output shaft of automatic transmission with hydraulic torque converter connects with diff.Automatic transmission with hydraulic torque converter has the input shaft revolution ratio different with output shaft.Diff 31 is arranged between first group of wheel 1L and the 1R.In described embodiment, used the automatic transmission shaft of RE4F03B type, it comprises torque converter, four gear transmissions and diff.The further information of the automatic transmission shaft of relevant RE4F03B type can be consulted the Co. by Nissan Motor, and C-6 is to the C-22 page or leaf in the service manual that Limited delivered in February, 2002 " Nissan MARCH ".

Second power system comprises reducing gear 11 that connects with electric traction electrical motor 4 and the diff 13 that connects with power-transfer clutch 12.Diff 13 is arranged between second group of wheel 3L and the 3R.Power-transfer clutch 12 has the input shaft that connects with the output block of reducing gear 11.The output shaft of power-transfer clutch 12 connects with the input block of diff 13.In described embodiment, use the integrated driver element that comprises reducing gear, magnetic clutch and diff.The further information of relevant this integrated driver element can be consulted the MotorCo. by Nissan, and C-6 is to C-13 page or leaf (particularly C-10 page or leaf) in the service manual that Limited delivered in September, 2002 " Nissan MARGH ".

In described embodiment, power-transfer clutch 12 is the magnetic clutchs that dispose cam-actuated guiding power-transfer clutch.Be exciting coil, power-transfer clutch 12 is connected with unshowned power supply.The technical description how relevant cam-actuated guiding power-transfer clutch works is consulted the US-A 5,464,084 that delivers November 7 nineteen ninety-five, and this document is incorporated herein by reference.

In described embodiment, first group of wheel is respectively front left wheel 1L and right front wheel 1R, and second group of wheel is respectively left back wheel 3L and right rear wheel 3R.The present invention is not subjected to the restriction of this example.First group of wheel can be respectively left back wheel and right rear wheel, and second group of wheel can be respectively front left wheel and right front wheel.With the carrying out of discussing, should understand after power-transfer clutch 12 engagements, when motor torque to the power system gap (play) of driving motor or second group of

wheel

3L and 3R transmission when being eliminated, the operation of the 4WD pattern of automobile is ready.

About second power system, electrical motor 4 relies on electric energy to drive.Power supply can be a battery.Yet, in described example of the present invention, power supply from driving engine 2 electrical generator 7 that connects of power mutually.The endless belt 6 that electrical generator 7 and driving engine 2 mutual power are connected makes electrical generator 7 rotate with rotational speed N h with belt pulley, and this rotational speed N h can be expressed by engine speed Ne and belt pulley ratio.Belt pulley ratio R p is two ratios between the skin speed wheel, and one of them is installed on the engine output shaft, and another is installed on the generator shaft.

When electrical generator 7 is applied magnetic field electric current of generator Ifh, electrical generator 7 becomes the load of driving engine 2, and response overcomes the engine torque generation electric energy of this load.Hereinafter this engine torque is called " load torque Th ".Cable 9 is connected electrical generator 7 with electrical motor 4.Connection box 10 is arranged in the cable 9 between electrical generator 7 and the electrical motor 4.Relay 24 is arranged so that selectively to electrical motor 4 supply electric energy in connection box 10.

Continuation is with reference to figure 1, and wheel speed sensors 27FL, 27FR, 27RL and 27RR monitor the vehicle wheel rotational speed related with it respectively.Engine speed sensor 21 detects the parameter of indication driving engine 2 rotating speeds.

With reference to figure 4, the current sensor 23 in the connection box 10 is measured the electric current that is supplied to electrical motor 4 electric energy by electrical generator 7 simultaneously.The current measurement of surveying be the armature current Ia of electrical motor 4.Motor speed sensor 26 detects the rotational speed N m of electrical motor 4 axle drive shafts.Set thermally dependent resistor 25 is used to detect the temperature of electrical motor 4.

Gear shift detector 32, sensor 35,62,27FL, 27FR, 27RL, 27RR, 21,60 and 26, and the output signal of thermally dependent resistor 25 is used as the input of 4WD controller 8.4WD controller 8 comprises the microprocessor 50 that can communicate by letter with computer read/write memory medium 52.As be familiar with this technical field personnel understood, for example computer read/write memory medium 52 can comprise random-access memory (ram) 54, read-only memory (ROM) (ROM) 56 and/or keep memory device (KAM) 58.

With reference to figure 4, electrical generator order c1 (duty ratio) handled and produces by the 4WD controller to input.Electrical generator order c1 is used as the input of the voltage regulator 22 of electrical generator 7.Voltage regulator 22 is adjusted to the indicated numerical value by electrical generator order c1 with magnetic field electric current of generator Ifh.Voltage regulator 22 detects the output voltage V of electrical generator.The generator output voltage V that is detected is fed to 4WD controller 8.Under the control of 4WD controller 8, voltage regulator 22 is adjusted magnetic field electric current of generator Ifh.Adjusting field current Ifh just adjusts load torque Th and generator output voltage V.Like this, 4WD controller 8 can control load torque T h and generator output voltage V.

4WD controller 8 produces the relay order that is used for relay 24.The order of response relay, relay 24 controls offer the voltage (or electric current) of electrical motor 4.

4WD controller 8 produces the electrical motor order that is used for electrical motor 4, thereby regulates motor field electric current I fm.Regulating motor field electric current I fm can adjust motor torque Tm.

4WD controller 8 produces the power-transfer clutch order that is used for power-transfer clutch 12.The responsive clutch order, power-transfer clutch 12 engagements or separation.

Block scheme among Fig. 5 is represented the software or the hardware component of 4WD controller 8.

In exemplary case according to the present invention, electrical generator function unit 8A receives the expectation value of generator voltage V.Calculate the expectation value of generator voltage V at generator voltage (V) the calculating unit 8G place of expectation.Electrical generator function unit 8A determines electrical generator order c1 with duty ratio (%) form.This electrical generator order c1 offers voltage regulator 22.Response electrical generator order c1, voltage regulator 22 is adjusted magnetic field electric current of generator Ifh, makes electrical generator 7 outputs reach the voltage V of desired value level.

Relay function unit 8B produces the relay order.The relay order offers the relay 24 in the connection box 10.

Electric motor-controlling components 8C imports relevant motor speed Nm, about the information of electrical motor (induction) voltage E and relevant motor armature electric current (motor current) Ia.Motor armature electric current I a is confirmed as the function of motor torque Tm and motor field electric current I fm.Therefore, if motor field electric current I fm is constant, motor armature electric current I a determines motor torque Tm.Electric motor-controlling components 8C adjusts motor current Ifm.

Clutch components 8D receives clutches engaged/separation order from power system gap adjustment parts 8H.The responsive clutch order provides the electric current of the coil of the power-transfer clutch 12 of flowing through by control, and the state of power-transfer clutch 12 is controlled.

Expectation load torque (Th) calculating unit 8E determines the expectation value of load torque Th.

Expectation load torque killer parts 8F compares the expectation value of load torque Th and the maximum load capability HQ of electrical generator 7.When the expectation value of load torque Th surpassed maximum load capability HQ, expectation load limiter parts 8F calculated interference moment of torsion Δ Tb (Δ Tb=Th-HQ), and maximum load capability HQ is made as Th.Expect load limiter parts 8F calculation engine upper torque limit TeM (TeM=Te-Δ Tb, wherein Te is the currency of engine torque), and engine torque upper limit TeM is outputed to engine controller 18.

Refer now to Fig. 2, the work of the flowcharting engine controller 18 among Fig. 2.

In frame S10, engine controller 18 is determined the expectation value of engine torque TeN according to the output signal (APO) of accelerator pedal sensor 60.

In next frame S20, engine controller 18 determines whether that this upper limit TeM will be determined with the engine torque upper limit TeM feed-in from 4WD controller 8 in Fig. 7 center S530.Control logic turns to frame S30 if satisfy condition.If the control logic that do not satisfy condition turns to frame S50.

In frame S30, engine controller 18 determines whether that the expectation value of engine torque TeN is greater than engine torque upper limit TeM.If satisfy condition, control logic turns to frame S40.If do not satisfy condition, control logic turns to frame S50.

In frame S40, engine controller 18 is made as the engine torque upper limit TeM expectation value of engine torque TeN.

In next frame S50, engine controller 18 is determined the currency of engine torque Te according to accelerator pedal drafts APO and engine speed Ne that the output signal by accelerator pedal sensors 60 and engine speed sensor 21 provides.In the currency of determining engine torque Te, engine controller 18 can use the map mode of searching shown in Figure 15 in US 6,434, the 469 B1 files of delivering as on August 13rd, 2002, and this document is incorporated herein by reference.

In next frame S60, engine controller 18 calculation deviation Δ Te ', can followingly represent:

ΔTe’＝TeN-Te (1)

In next frame S70, engine controller 18 is that deviation delta Te ' determines the change amount Δ θ at throttle gate open angle θ, and determined change amount Δ θ is outputed to TCS controller 20, so that sub-throttle gate 16 has correspondingly action.

With reference to figure 3, TCS controller 20 is carried out the function that suppresses to quicken slip, and this acceleration is slided and occurred in drive wheel, i.e.

front vehicle wheel

1L and 1R in the present embodiment.Take place in case detected this acceleration slip, TCS controller 20 cuts out sub-throttle gate 16 to reduce the output of driving engine, and this process and vehicle drive person are separate to the manipulation of main throttle 15.Provide TCS sign TSCFLG, this sign is carried out above-mentioned engine torque is reduced at TCS and is set when control is quickened to slide with inhibition.

Flowcharting TCS controller 20 among Fig. 3 above-mentionedly reduces the workflow of control to suppress to quicken to slide, i.e. TCS control to engine torque carrying out.

In frame S100, having determined whether quickens to slide takes place.If take place, control logic turns to frame S110.If do not take place, control logic just turns to frame S140.

At frame S110, TCSFLG is set, and in frame S140, TCSFLG is eliminated.After TCSFLG was eliminated, the expectation value θ of sub-throttle gate 16 open angles was set to and equals open angle θ max, and open angle θ max is greater than the currency of any open angle, and main throttle 15 may adopt this open angle θ max.Then, TCS controller 20 is adjusted to open angle θ max with sub-throttle gate 16.Be opened to open angle θ max with sub-throttle gate 16, main throttle 15 is obtained the control to engine output torque.

After TCSFLG was set in frame S110, control logic turned to frame S120.At frame S120, determine so-called sliding ratio A.Sliding ratio A is expressed as follows:

A = \frac{V_{WF} - V_{WR}}{V_{WR}} - - - (2)

Wherein:

V _WFIt is the average velociity of front-wheel;

V _WRIt is the average velociity of trailing wheel.

At next frame S130, the expectation value θ of sub-throttle gate 16 open angles is determined by following computing formula.

θ＝K6×A (3)

Wherein:

K6 is gain.

Consider the deviation between current and the sliding ratio A before, gain K6 can have different numerical value.

In the present embodiment, car equipment has pull-in control system (TCS).TCS comprises TCS controller 20.TCS judges or monitors the ground-surface coefficient of friction to determine whether to carry out traction control.TCS carries out traction control when the ground-surface coefficient of friction is low, and sign TCSFLG set in will operating.When the ground-surface coefficient of friction was low, it is in running order that sign TCSFLG is set (TCSFLG=1) expression traction control.When the ground-surface coefficient of friction was not low, sign TCSFLG was eliminated or reset (TCSFLG=0).At present embodiment, sign TCSFLG is as the low indicating device of expression road surface coefficient of friction (μ).

The flowcharting of Fig. 6 is according to the service condition that is used to control an embodiment of the system that starts the automobile process of the present invention.The present invention realizes expectation load torque (Th) calculating unit 8E with software in control program.

With reference to figure 6, expectation load torque Th calculates in frame S400, S410, S420 and S430.Be calculation expectation load torque Th, determine to produce the moment of torsion expectation value T Δ V that is used to be applied to

rear wheel

3L and 3R by electrical motor 4 at frame S360 or S390.There are two treating processs to be used for determining the moment of torsion expectation value T Δ V that applies to rear wheel 3L and 3R.Be convenient and describe that two treating processs are called first process or based on the moment of torsion process, and second process or based on sliding process.Frame S350 and S360 represent first process.Frame S370, S380 and S390 represent second process.

According to first or based on the process of moment of torsion, determine to be applied to the moment of torsion expectation value T Δ V of

rear wheel

3L and 3R according to the output torque of the driving engine 15 that is applied to front vehicle wheel 1L and 1R.The accelerator pedal of response accelerator 17 is depressed (APO) angle, determines the output torque of driving engine 15.APO expresses driver's requirement by accelerator 17.Therefore, at the requirement decision expectation value T Δ V of first process by the driver.

According to second or based on the process of sliding, determine to be applied to the moment of torsion expectation value T Δ V of

rear wheel

3L and 3R at the acceleration slip Δ VF of

front vehicle wheel

1L and 1R generation.

Among Fig. 6, frame S300, S310, S320, S330, S340, S440, S450 and S460 represent to determine the logical block of a certain process in first process of carrying out and second process.

According to logical block shown in Figure 6, determine speed of a motor vehicle threshold value or threshold speed α.The speed of a motor vehicle of automobile or speed V _CarObtain monitoring.Vehicle velocity V _CarCompare (seeing frame S330 or S340) with speed of a motor vehicle threshold alpha.Work as vehicle velocity V _CarCarry out first process when being less than or equal to speed of a motor vehicle threshold alpha.Work as vehicle velocity V _CarSurpass or carry out second process when being higher than speed of a motor vehicle threshold alpha gradually.In the present embodiment, road surface coefficient of friction μ determines speed of a motor vehicle threshold alpha, so that improve speed of a motor vehicle threshold alpha when road surface coefficient of friction μ reduces.The available information that relevant road coefficient of friction changes can be continuous or disperse.If continuous, speed of a motor vehicle threshold alpha can increase continuously.If that disperse and have two grades, speed of a motor vehicle threshold alpha can be brought up to the higher speed of a motor vehicle from the low speed of a motor vehicle.In diagram of circuit shown in Figure 6, the reduction of road coefficient of friction μ makes speed of a motor vehicle threshold alpha bring up to the 10km/h speed of a motor vehicle (seeing frame S340) from the lower 5km/h speed of a motor vehicle (seeing frame S330).

Continuation is with reference to figure 6, clocklike to repeat diagram of circuit at interval.At frame S300,4WD controller 8 determines whether to remove so-called low μ sign T _μFLG.If low μ sign T in frame S300 _μFLG is eliminated or (the T that resets _μFLG=0), logic steering frame S310.If low μ sign T in frame S330 _μFLG is set (T _μFLG=1), logic steering frame S340.

Carrying out along with discussing it should be noted that, in case that road coefficient of friction μ is confirmed as is low, logic just turns to frame S310 from frame S300, turns to frame S320 then, low μ sign T _μFLG switches to one (1) grade from zero (0) level.Low μ sign T _μFLG remains on one (1) grade continuously, up to satisfying predetermined condition.Satisfying predetermined condition then carries out based on the process of sliding to determine the expectation value T Δ V of moment of torsion according to acceleration slip Δ VF.At present embodiment, when when the automobile starting process satisfies predetermined condition, logic forwards S460 from frame S340 to through frame S440 and S450.At frame S460, low μ sign T _μFLG is eliminated.After the frame S460, logic so far is finished based on the process of sliding through frame S370, S380 and S390.

In the frame S310 of Fig. 6,4WD controller 8 determines whether clear flag TCSFLG (TCSFLG=0).If removed, logic steering frame S320.Do not remove if, then logic steering frame S320.

At frame S330,4WD controller 8 determines whether vehicle velocity V _CarBe less than or equal to 5km/h, this speed is set to threshold value speed of a motor vehicle α.If satisfy condition, logic steering frame S350 is to carry out the process based on moment of torsion.If do not satisfy condition, logic steering frame S370 is to carry out based on the process of sliding.

As previously mentioned, the process based on moment of torsion is to carry out at frame S350 and S360.At frame S350,4WD controller 8 is from the information of acceleration sensor 60 inputs about APO.At next frame S360,4WD controller 8 is determined the expectation value T Δ V of moment of torsion, can be expressed as:

TΔV＝K4×APO (4)

Wherein:

K4 is for example by the determined gain of simulation.

As discussed above, APO represents to be applied to the driving torque of front vehicle wheel 1L and 1R.Owing to be confirmed as the function of APO, the expectation value T Δ V of the moment of torsion of being expressed by formula (4) depends on the driving torque that is applied to front vehicle wheel 1L and 1R.Thereby, can be described as expectation value T Δ V based on moment of torsion.

As previously mentioned, carry out at frame S370, S380 and S390 based on the process of sliding.At frame S370,4WD controller 8 is imported about wheel speed V from wheel speed sensors 27FL, 27FR, 27RL and 27RR _WFL, V _WFR, V _WRLAnd V _WRRInformation, to determine the average velociity V of front vehicle wheel _WFAverage velociity V with rear wheel _WR, can followingly express:

V_{WF} = \frac{V_{WFL} + V_{WFR}}{2}

V_{WR} = \frac{V_{WRL} + V_{WRR}}{2} - - - (5)

At next frame S380,4WD controller 8 is determined to quicken to slide or sliding velocity Δ VF, and it is the quantity of the acceleration slip of front vehicle wheel 1L and 1R.Quickening slip Δ VF can followingly express:

ΔVF＝V _WF-V _WR (6)

At next frame S390,4WD controller 8 is determined the expectation value T Δ V of moment of torsion, can be expressed as:

TΔV＝K1×ΔVF (7)

Wherein:

K1 is for example by the determined gain of simulation.

Owing to be confirmed as the function of speed of a motor vehicle slip Δ VF, the expectation value T Δ V of the moment of torsion of being expressed by formula (7) depends on the acceleration that is applied to

front vehicle wheel

1L and 1R and slides.Thereby, can be described as based on the expectation value T Δ V that slides.The expectation value T Δ V based on sliding of moment of torsion represents to be absorbed to suppress to quicken the engine torque of slip Δ F.

After in frame S360 or S390, determining the expectation value T Δ V of moment of torsion, logic steering frame S400.As previously mentioned, calculation expectation load torque Th in frame S400, S410, S420 and S430.

At frame S400,4WD controller 8 determines whether the expectation value T Δ V of moment of torsion equals predetermined value 0 (zero).If satisfy condition (T Δ V=0), logic steering frame S410.If do not satisfy condition (T Δ V＞0), logic steering frame S420.

At frame 410, the expectation value of 4WD controller 8 load torque Th before returning starting point is set to 0 (Th ← 0).

At frame S420, the currency of 4WD controller 8 calculated load torque T G.The currency of load torque TG is expressed with following formula:

TG = K 2 \times \frac{V \times Ia}{k 3 \times Nh} - - - (8)

Wherein: V is the voltage of electrical generator 7;

Ia is the armature current of electrical generator 7;

Nh is the rotating speed of electrical generator 7;

K3 is an efficient; With

K2 is a coefficient.

At next frame S430,4WD controller 8 before returning starting point, the expectation value of calculated load torque T h.The expectation value of load torque Th can be expressed as:

Th＝TG+TΔV (9)

Reference block S300, S310 and S330 should notice that logic always forwards frame S330 under the not low situation of road coefficient of friction μ.More particularly, road coefficient of friction μ is not less than the coefficient of friction threshold value, keeps each low μ sign T _μFLG and sign TCSFLG equal 0 (zero).In the case, work as vehicle velocity V _CarWhen being less than or equal to 5km/h, carry out frame S350 and S360 first or based on the process of moment of torsion, work as vehicle velocity V _CarWhen surpassing 5km/h, carry out frame S370, S380 and S390 second or based on the process of sliding.Like this, in the case, it is 5km/h that speed of a motor vehicle threshold alpha continues.

After road coefficient of friction μ was lower than the threshold value coefficient of friction gradually and makes sign TCSFLG is set, logic forwarded frame S320 to from frame S310.At frame S320,4WD controller 8 will hang down μ sign T _μFLG set.At low μ sign T _μAfter FLG was set, 4WD controller 8 improved threshold value speed of a motor vehicle α immediately, is increased to higher 10km/h from lower 5km/h.Say that simply when road surface coefficient of friction μ was low, threshold value speed of a motor vehicle α brought up to higher speed of a motor vehicle 10km/h.

At low μ sign T _μIn the circulation after FLG is set, logic directly forwards frame S340 to from frame S300.

At frame S340,4WD controller 8 is determined vehicle velocity V _CarWhether be less than or equal to 10km/h, this speed of a motor vehicle now has been made as threshold value speed of a motor vehicle α.If satisfy condition, logic forwards frame S350 to and continues to carry out based on the moment of torsion process.If do not satisfy condition, logic steering frame S440.

At frame S440,4WD controller 8 increases counter cnt or counting (counts up).

At next frame S450,4WD controller 8 determines whether the count value of counter cnts meets or exceeds predetermined count value, this numerical value be preset time 10 seconds by diagram of circuit from Fig. 6 begin remove the merchant who obtains to the time gap between the beginning of identical diagram of circuit next time.If do not satisfy condition, logic forwards frame S350 to continue to carry out the process based on moment of torsion from frame S450.If satisfy condition, logic steering frame S460.

At frame S460,4WD controller 8 is to each low μ sign T _μFLG and make counter cnt be reset to 0 (zero).Logic forwards frame S370 to carry out based on sliding process from frame S460.

Provide frame S440 and S450 and frame S460 make counting machine reset (CNT=0) work as vehicle velocity V in order to eliminate _CarContingent swing when surpassing 10km/h.

In diagram of circuit shown in Figure 6, consider now diagram of circuit is how to change to handle to work as vehicle velocity V _CarNeed eliminate the situation of contingent swing when temporarily surpassing 5km/h.In this example, the "No" branch road of frame S330 is the branch of frame S370.The "No" branch road of frame S330 is connected to the cooresponding frame with S440.Be equivalent to after the frame of S440 is the frame that is equivalent to S450.The frame that is equivalent to S450 has the "No" branch road and is connected with frame S350.The "Yes" branch road that is equivalent to the frame of S450 is connected with the frame that the content of counter cnt is eliminated.Frame S370 follows the frame that counter cnt is eliminated.

Swing if swing is minor issue or reality, logic directly forwards frame S450 to from frame S340 behind removal frame S440 and the S450

For example, such characteristic is clearly supported about the description of frame S440 and S450 in the front, and this characteristic is that current intelligence should carry out first or based on the moment of torsion process, unless vehicle velocity V continuously _CarSurpass threshold value speed of a motor vehicle α (5km/h or 10km/h) continuously and reach for example 10 seconds schedule time.

Later on reference to Fig. 9 A to 9E to discussing by diagram of circuit 6 the operation described.Before the discussion, describe expectation load torque killer parts 8F (see figure 5) with reference to figure 7 earlier, describe electrical generator expectation voltage (V) calculating unit 8G (see figure 5) with reference to figure 8 then.

The flowcharting of Fig. 7 is used for realizing with software the control program of expectation load torque killer parts 8F.

At frame S500,4WD controller 8 determines whether the expectation value of load torque Th surpasses the maximum load capability HQ of electrical generator 7.If satisfy condition (Th＞HQ), logic steering frame S510.(TH≤HQ), logic does not turn back to starting point if do not satisfy condition.

At frame S510,4WD controller 8 calculates interference moment of torsion Δ Tb, following expression:

ΔTb＝Th-HQ (10)

At next frame S520,4WD controller 8 is determined the current numerical value of engine torque Te according to APO and Ne, and APO and Ne are provided by the output signal of acceleration sensor 60 and engine speed sensor 21 respectively.In determining the current numerical value of engine torque Te, 4WD controller 8 may use together the map mode of searching shown in Figure 15 among as a reference US 6,434,469 B1.

At frame S530,4WD controller 8 calculation engine upper torque limit TeM, can followingly express:

TeM＝Te-ΔTb (11)

At identical frame S530,4WD controller 8 outputs to engine controller 18 (seeing the frame S20 among Fig. 2) with engine torque upper limit TeM.

At next frame S540,4WD controller 8 is provided with maximum load capability HQ and turns round expectation value Th as the load that is offered driving engine 2 by electrical generator 7.

Then, flowcharting is used for realizing with software the control program of electrical generator expectation voltage (V) calculating unit 8G among Fig. 8.

At frame S600,4WD controller 8 determines that whether expectation value T Δ V at the frame S360 of Fig. 6 or the fixed moment of torsion of S390 is greater than 0 (zero).If satisfy condition (T Δ V＞0), logic steering frame S610.If do not satisfy condition (T Δ V=0), logic is returned starting point.

At frame S610,4WD controller 8 is from the information of motor speed sensor 26 input motor rotational speed N m.4WD controller 8 is determined the expectation value with respect to the motor field electric current I fm of motor speed Nm from look-up table for example.4WD controller 8 sends the expectation value of determined motor field electric current I fm to electric motor-controlling components 8C (see figure 5).

About variation along with motor speed Nm expectation value of motor field electric current I fm when the different numerical value, as as shown in the frame S610, motor field electric current I fm remains unchanged in the scope that rotating speed is lower than predetermined value, but electric current descends when rotating speed equals or exceeds predetermined value.

Except motor field electric current I fm is reduced, otherwise motor-induced voltage E will improve, and is difficult to guarantee to produce under high like this rotating speed flowing of the required motor armature electric current I a of enough motor torques.Therefore, when high rotating speed equals or exceeds predetermined value, by reducing the rising that motor field electric current I fm prevents induced voltage E, to guarantee to be used to produce flowing of the required motor armature electric current I a of sufficiently high electric torque Tm.

Diagrammatic representation motor field electric current I fm in frame S610 drops to low-level in discrete mode from high level.Need be so that the characteristic of level and smooth (smoother) motor torque to be provided if produce, rather than provide motor field electric current I fm to change two levels, motor field electric current I fm can continuously change with the different value of motor speed Nm.The continuous variation of motor field electric current I fm causes needing motor torque Tm is revised continuously to produce the expectation value of motor torque Tm for the different value of motor speed Nm.

At next frame S620,4WD controller 8 is determined with respect to the expectation value of motor field electric current I fm and the motor-induced voltage E of motor speed Nm from for example searching map.

At frame S630, the expectation value of the expectation value calculating motor torque T m that 4WD controller 8 uses at the determined load torque Th of the control program of Fig. 7.Motor torque Tm can be expressed as follows:

Tm = \frac{Th \times Ne \times ηge \times ηmot}{Nm} - - - (12)

Wherein: Tm is a motor torque;

Nm is a motor speed;

Th is a load torque;

Ne is an engine speed;

η ge is a dynamo efficiency; With

η mot is a motor efficiency.

At next frame S640,4WD controller 8 is determined the expectation value as the motor armature electric current I a of the function of the expectation value of the expectation value of motor torque Tm and motor field electric current I fm.

At next frame S650, the expectation value of 4WD controller 8 calculating generator voltage V is expressed as follows:

V＝Ia×R+E (13)

Wherein:

R is the coil resistance sum of the resistance and the electrical motor 4 of cable 9.

According to the diagram of circuit of Fig. 8, the expectation value of generator voltage V with due regard to is being determined in frame S250 to electrical motor 4 backs.The mode of determining the expectation value of generator voltage is not subjected to the restriction of this case description.Allow as situation, the expectation value of generator voltage V can be used as the function of load torque Th expectation value and directly determines.

The present invention discloses in conjunction with the automobile with electrical motor 4, and this electrical motor 4 is as the driving torque source that applies moment of torsion to rear wheel 3L and 3R.The present invention can be applied in the automobile of the 4WD drive system with other type.The 4WD drive system that comprises part-time case (transfer) is exactly an example.

Can understand to some extent embodiments of the invention described above with reference to following statement.

In order to make static automobile sport, need apply bigger driving torque to front vehicle wheel 1L and 1R.The driver depresses accelerator pedal 17 makes driving engine 2 produce enough big moment of torsion so that powerful driving torque to be provided to wheel.Because it is very big to be applied to the driving torque of

front vehicle wheel

1L and 1R,,

front vehicle wheel

1L and 1R tendency slide so producing.Need suppress the tendency that this generation is slided effectively, make it be in fully low level.According to embodiment,, address this need from the 4WD that repeats first process (seeing Fig. 6 center S350 and S360) and derived based on torque T Δ V by response APO.With APO pro rata driving torque be applied to rear wheel 3L and 3R.Use APO as the control input, driving torque has been realized feedforward 4WD control as control output.This feedforward 4WD control can suppress front vehicle wheel 1L effectively and 1R produces the tendency of sliding.

For pursuing and the good the same outstanding fuel economy of acceleration capability, the operating range limiting that feedforward 4WD is controlled is in required minimum degree behind the automobile starting.Behind the automobile starting, the speed of a motor vehicle and time are two variablees that increase continuously.But minimum degree with these variablees and threshold qualification meet requirements.In an embodiment, select vehicle velocity V behind the automobile starting _CarExample as the variable that increases continuously.Set up threshold value speed of a motor vehicle α (=5km/h).Vehicle velocity V _Carα compares with the threshold value speed of a motor vehicle.Work as vehicle velocity V behind the automobile starting _CarWhen being less than or equal to threshold value speed of a motor vehicle α, feedforward 4WD control can provide good pickup.We remember determine to carry out first process (Fig. 6 center S350 and S360), and thereby repeat this process feedforward 4WD control can be realized.

As previously mentioned, because making, the delay of time quickens to slide generation inevitably in the transition period.The driving situation that embodiments of the invention find this of short duration acceleration of may command to slide.Two major influence factors relevant with of short duration acceleration slip are road surface coefficient of friction μ and driving torque.In an embodiment, road pavement coefficient of friction μ and vehicle velocity V _CarMonitor to determine whether the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.Feedforward 4WD control response first or based on the expectation value T Δ V of moment of torsion applies driving torque to

rear wheel

3L and 3R, and this expectation value is that to respond driver's power requirement (APO) determined.Feed back 2/4WD control response second or based on the expectation value T Δ V that slides, apply driving torque to

rear wheel

3L and 3R, this expectation value is that response is quickened to slide determined.

As mentioned above, vehicle velocity V _CarCoefficient of friction μ is equally monitored with the road surface.Significantly, of short duration acceleration slip depends on road surface coefficient of friction μ.Along with vehicle velocity V _CarRaising, the deviation of the front wheel rotation speed and the speed of a motor vehicle is dwindled gradually.In addition, work as vehicle velocity V _CarBe raised to and cross shift-up point, the change-speed box that is associated improves gear.This descends the driving torque that is applied to rear wheel 3L and 3R.Therefore, vehicle velocity V _CarIn startup and car acceleration process subsequently, play the indicating device effect that the indication driving torque changes.

As preceding described to frame S300, S310 and S320, monitoring sign TCSFLG is to determine whether road surface coefficient of friction μ is lower.

According to embodiment, as shown in Figure 6, work as vehicle velocity V _CarWhen surpassing threshold value speed of a motor vehicle α, if road surface coefficient of friction μ keeps high value, the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.By being confirmed this with the logic flow of lower edge frame S300, S310, S330, S370, S380, S390, S400, S420 and S430.At this example,, higher road surface coefficient of friction μ is inhibited because making transition quicken to slide.

According to embodiment, as shown in Figure 6, work as vehicle velocity V _CarWhen surpassing threshold value speed of a motor vehicle α, if road surface coefficient of friction μ is in than low value, the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.By being confirmed this with the logic flow of lower edge frame S300, S310, S340, S350, S360, S390, S400, S420 and S430.Keep this logic flow up to vehicle velocity V _CarThe threshold value speed of a motor vehicle that surpasses another 10km/h.Like this, if road surface coefficient of friction μ is in than low value, keep feedforward 4WD control up to vehicle velocity V _CarThe threshold value speed of a motor vehicle that surpasses another 10km/h.Automobile drives to have with the 4WD pattern to be optimized and stable acceleration/accel, any bigger acceleration does not take place slide.

Along with vehicle velocity V _CarRaising, the deviation of the vehicle wheel rotational speed and the speed of a motor vehicle is dwindled gradually, at the change-speed box direction ratio changing that upgrades, the driving torque that is applied to

rear wheel

3L and 3R is descended.In Fig. 6, work as vehicle velocity V _CarWhen surpassing the threshold value speed of a motor vehicle of 10km/h, even road surface coefficient of friction μ is in than low value, the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.By being confirmed this with the logic flow of lower edge frame S300, S320, S340, S440, S450, S460, S370, S380, S390, S400, S420 and S430.At this example, because driving torque is lower, so the transition acceleration is slided less.

According to embodiment, in Fig. 6, if road surface coefficient of friction μ is in high value, in vehicle velocity V _CarAfter surpassing the threshold value speed of a motor vehicle of 5km/h, keep feedforward 4WD control in for example predetermined 10 seconds time cycle.If road surface coefficient of friction μ is in than low value, in vehicle velocity V _CarAfter surpassing the threshold value speed of a motor vehicle of the 10km/h that improves, keep feedforward 4WD control in the preset time cycle.By being confirmed this with the logic flow of lower edge frame S300, S340, S440, S450, S350, S360, S400, S420 and S430.

If road surface coefficient of friction μ is in high value, work as vehicle velocity V _CarWhen surpassing the threshold value speed of a motor vehicle of 5km/h, if or road surface coefficient of friction μ be in than low value, in vehicle velocity V _CarDuring the threshold value speed of a motor vehicle of the 10km/h that surpass to improve, make the adjustment that changes drive pattern after, carry out feedback 2/4WD control.Compare with feedback 2/4WD control, 4WD only sets up when the slip of acceleration is arranged.Like this because the opereating specification of setting up the 4WD pattern is limited in quickening the required minimum zone that slides and take place, institute so that fuel economy be improved.

According to embodiment, the opereating specification of feedforward 4WD control can be limited in required minimum zone, promptly is in than low value except road surface coefficient of friction μ, should be by the fully low speed of a motor vehicle being set as the threshold value speed of a motor vehicle, and for example 5km/h is suppressed at the acceleration slip between the starting period.This can make fuel economy improve.

With reference to Fig. 9 A to 9E, whole lines of being painted be illustrated on the road with low μ value start with subsequently car acceleration process in the service condition of embodiment.Be purpose relatively, dotted line represents always to carry out the service condition of the system from feedforward 4WD control break to feedback 2/4WD control.

When the driver depresses accelerator pedal 17 (seeing Fig. 9 A), according to the startup of embodiment and process subsequently at time t ₀Beginning.At time t ₀After the time t that follows closely ₁, initial acceleration slip (seeing Fig. 9 B) beginning will indicate TCSFLG set (seeing Fig. 9 D), thereby make low μ sign T _μFLG set (seeing Fig. 9 E).Time t ₁Afterwards, threshold value speed of a motor vehicle α changes to 10km/h from 5km/h at once.Then, with vehicle velocity V _Car10km/h repeatedly compares with the threshold value speed of a motor vehicle.

At time t ₁Time t afterwards ₂, because feedforward 4WD control has suppressed initial acceleration slip (seeing Fig. 9 B), sign TCSFLG be reset (seeing Fig. 9 D).Low μ sign T _μFLG keeps original value (seeing Fig. 9 E), thereby keeps threshold value speed of a motor vehicle α to be in the 10km/h speed of raising.

Subsequently at time t ₅, vehicle velocity V _CarSurpass the threshold value speed of a motor vehicle 10km/h that improves.Then, in the time cycle vehicle velocity V of being scheduled to 10 seconds _CarIt is above up to time t to remain on 10km/h ₆At t ₅To t ₆During this time, even vehicle velocity V _CarAfter surpassing the threshold value speed of a motor vehicle 10km/h that improves, keep feedforward 4WD control continuously.

At time t ₆, change feedback 2/4WD control into, low μ sign T _μFLG be reset (seeing Fig. 9 E).Time t ₆Afterwards, if do not take place to quicken to slide, 2WD is set up in feedback 2/4WD control immediately.

About the service condition of conventional system, at time t ₃, work as vehicle velocity V _CarWhen surpassing threshold value speed of a motor vehicle 5km/h, feedforward 4WD control is under an embargo.Because at time t ₃After begin conversion immediately from the 4WD pattern to the 2WD pattern, at time t ₄Beginning to take place transition quickens to slide.Respond this acceleration and slide, 4WD is set up in feedback 2/4WD control.At time t ₄Afterwards, the handle of

front vehicle wheel

1L and 1R surpasses handle restriction (seeing Fig. 9 C).

In an embodiment, response is in the road surface coefficient of friction μ than low value, and the single vehicle speed value of 10km/h is set.The present invention is not subjected to the restriction of this example.The road surface coefficient of friction μ of response varying level, can be provided with one or more other or middle vehicle speed value.

In an embodiment, coefficient of friction μ in road surface changes to low-level until vehicle velocity V during the course _CarThis separate event of the threshold value speed of a motor vehicle that reaches 5km/h provides the signal of the threshold value speed of a motor vehicle of the 10km/h that improves.The present invention is not subjected to the restriction of this example.Another example of the signal that may provide is to be lower than and near the level of the road surface coefficient of friction of the threshold value speed of a motor vehicle of 5km/h in the speed of a motor vehicle.Another example be before starting to the threshold value speed of a motor vehicle that reaches 5km/h between, the estimation of the road surface coefficient of friction under all speed of a motor vehicle or the aviation value of measurement

In the diagram of circuit of Fig. 6, work as vehicle velocity V _CarWhen being less than or equal to the threshold value speed of a motor vehicle of 5km/h, the threshold value speed of a motor vehicle of the 10km/h of raising after being set, sign TCSFLG is set immediately.For removing frame S340,, can remove the threshold value speed of a motor vehicle of the 10km/h of raising by the output branch of the "No" branch of frame S300 and frame S320 and frame S340 are separated.Separated "No" and output branch can be connected to the input branch of frame S330.The "No" branch of frame S330 is connected to the input branch of frame S370.New query frame is inserted in the "No" branch of frame S330.In this query frame, determine low μ sign T _μWhether FLG is set.If satisfy condition, logic steering frame S440.If do not satisfy condition, logic steering frame S370.

The control policy that provides as the diagram of circuit of above-mentioned modification is to work as vehicle velocity V _CarWhen surpassing the threshold value speed of a motor vehicle of 5km/h,, carry out feedforward 4WD control continuously in 10 second predetermined cycle if road surface coefficient of friction μ is in than low value.Because vehicle velocity V after 10 seconds _CarFrom 5km/h the increase of expection is arranged, under the speed of a motor vehicle that improves expectedly from feedforward 4WD control break to feedback 2/4WD control.

In an embodiment, used throttle gate to reach traction control by regulating driving engine.The present invention is not subjected to the restriction of the TCS of this type, can use the TCS of other type.Representational example is that TCS uses the ignition delay of single or combination to regulate, suspend igniting, reduce or suspend fuel supply, and regulating engine air throttle only is an example.

Flowcharting among Figure 10 is used to according to the present invention to control and starts and the service condition of another embodiment of the system of the accelerator of automobile or method subsequently.This embodiment is except providing new frame S700, S710, S720, S730 and S810 with frame S300, S310, S320, S340, S440, S450 and S460 in the alternate figures 6 in Figure 10, and is identical with the embodiment that at first discusses basically.In Fig. 6 and Figure 10, identical frame adopts identical reference number.

With reference to Figure 10, with regular time flowchart repeatedly at interval.At frame S700,4WD controller 8 is determined so-called low μ sign T _μWhether FLG is eliminated.If in frame S700, low μ sign T _μFLG is eliminated or (the T that resets _μFLG=0), logic steering frame S710.If in frame S700, low μ sign T _μFLG is set (T _μFLG=1), logic steering frame S730.

At frame S710,4WD controller 8 determines to quicken slip Δ F (Δ F=V _WF-V _WR) whether greater than for example threshold value 1 (km/h).If satisfy condition, 4WD controller 8 definite road surface coefficient of friction μ are in than low value and make logic steering frame S720.At frame S720,4WD controller 8 makes low μ sign T _μFLG set.Be equal to or less than 1km/h, logic steering frame S330 if quicken slip Δ F.In this example, 4WD controller 8 determines that road surface coefficient of friction μ is not in than low value or high value.

At frame S710, threshold value equals 1km/h rather than 0km/h to eliminate following possibility, that is: when turn or turn to during the very little difference of wheel speed may be considered to the speed of a motor vehicle and slide and take place.

After the frame S720, logic steering frame S730.At frame S730, the information of the shift pattern that the change-speed box that 4WD controller 8 bases are relevant is interior determines whether to set up the velocity ratio forward less than first velocity ratio.In other words, determine whether to set up second speed at frame S720.If set up the second speed ratio behind the first speed rising gear, logic turns to frame S330 from frame S730.

At frame S330,4WD controller 8 is determined vehicle velocity V _CarWhether be less than or equal to the threshold value speed of a motor vehicle of 5km/h.

In this part, frame S730 and S330 are stated.The threshold value speed of a motor vehicle of using in frame S330 is near one of the vehicle speed value the second speed that upgrades from first speed that change-speed box is arranged.It is under common driving situation change-speed box keep first speed than near one of vehicle speed value.Search second speed at frame S730 and represent that the road surface that has than low frictional factor μ allows

wheel

1L and 1R to rotate quickly, makes the regulation of the raising of the speed of a motor vehicle greater than expection.

Adopt in a like fashion with the diagram of circuit of Fig. 6, carry out process, carry out based on the process of sliding at frame S370, S380 and S390 based on moment of torsion at frame S350 and S360.After the frame S390, logic steering S810.At frame S810,4WD controller 8 makes low μ sign T _μFLG resets.

Adopt in a like fashion with the diagram of circuit of Fig. 6, work as vehicle velocity V _CarWhen being less than or equal to the threshold value speed of a motor vehicle of 5km/h, logic flow is carried out the process based on moment of torsion from frame S330 to S350.Work as vehicle velocity V _CarWhen surpassing the threshold value speed of a motor vehicle of 5km/h, logic flow is carried out from frame S330 to S370 based on the process of sliding.

According to embodiment shown in Figure 10, if road surface coefficient of friction μ is lower, even vehicle velocity V _CarAfter surpassing the threshold value speed of a motor vehicle of 5km/h, still keep feedforward 4WD control to second speed driving torque to be descended up to change-speed box rising gear.

In this embodiment, monitoring acceleration slip and shifting of transmission position are to determine whether activation point should be controlled to feedback 2/4WD from feedforward 4WD control break.Feedforward 4WD control response first or apply driving torque to

rear wheel

3L and 3R based on the prestige value T Δ V of moment of torsion phase, this expectation value T Δ V is the power requirement determined (seeing Figure 10 center S350 and S360) that responds the driver.Feed back 2/4WD control response second or apply driving torque to

rear wheel

3L and 3R based on the expectation value T Δ V that slides, this expectation value T Δ V is that slide determined (seeing Figure 10 center S370, S380 and S390) quickened in response.When change-speed box rising gear descended the driving torque that is applied to

rear wheel

3L and 3R, the size and the road surface coefficient of friction μ that quicken to slide were inversely proportional to.

Description to Figure 10 it should be noted that, in an embodiment, works as vehicle velocity V _CarWhen surpassing the threshold value speed of a motor vehicle, behind change-speed box generation rising gear, should be from feedforward 4WD control break to feedback 2/4WD control.

In the diagram of circuit of Figure 10, if desired to working as vehicle velocity V _CarContingent swing is eliminated when temporarily surpassing 5km/h, and the "No" branch road of frame S330 is the branch of drawing from frame S370.The "No" branch road of frame S330 is connected to the frame (see figure 6) that is equivalent to frame S440.Be equivalent to after the frame of S440 is the frame that is equivalent to S450.The frame that is equivalent to S450 has the "No" branch road and is connected with frame S350.The "Yes" branch road that is equivalent to the frame of S450 is connected with the frame that the content of counter cnt is eliminated.Counter cnt is eliminated in the frame before the frame S370.

Flowcharting among Figure 11 is used to according to the present invention to control and starts and the service condition of another embodiment of the system of the accelerator of automobile or method subsequently.This embodiment is except providing new frame S900, S920, S930, S940, S950 and S1010 with frame S300, S310, S320, S440, S450 and S460 in the alternate figures 6 in Figure 11, and is identical with the embodiment that at first discusses basically.In Fig. 6 and Figure 11, identical frame adopts identical reference number.

With reference to Figure 11, with regular time flowchart repeatedly at interval.At frame S900,4WD controller 8 determines whether switch sign SLCFLG is eliminated.If in frame S900, switch sign SLCFLG is eliminated or reset (SLCFLG=0), logic steering frame S330.If in frame S700, low μ sign T _μFLG is set (SLCFLG=1), logic steering frame S340.

At frame S330,4WD controller 8 is determined vehicle velocity V _CarWhether be less than or equal to the threshold value speed of a motor vehicle α of 5km/h.If satisfy condition, logic steering frame S920.If do not satisfy condition, logic steering comprises the process based on slip of frame S370, S380 and S390.

At frame S340,4WD controller 8 is determined vehicle velocity V _CarWhether be less than or equal to the threshold value speed of a motor vehicle α of 10km/h.If satisfy condition, logic steering comprises the process based on moment of torsion of frame S350 and S360.Do not turn to the process that comprises frame S370, S380 and S390 if do not satisfy conditional logic based on slip.

At frame S940,8 estimations of 4WD controller or calculating road surface coefficient of friction μ are expressed as follows

μ = \frac{K 5}{(WHEEL ACC .) - (VEHICLE ACC .)} - - - (14)

Wherein:

K5 is gain.

At next frame S930,4WD controller 8 determines whether road surface coefficient of friction μ is less than or equal to threshold value coefficient of friction μ ' (for example ,=0.2).If satisfy condition, logic steering frame S940.If do not satisfy condition, logic steering comprises the process based on moment of torsion of frame S350 and S360.

At frame 940,4WD controller 8 determines whether to have set up first speed at change-speed box.If satisfy condition, logic steering frame S950.If do not satisfy condition, logic steering is based on the frame S350 of the process of moment of torsion.

The threshold value speed of a motor vehicle of the 5km/h that frame S330 uses is lower than the speed of a motor vehicle of the gear that under normal circumstances should raise immediately.At frame S940, find that setting up first speed represents also to raise gear.At frame S940, find that not setting up first speed represents to have taken place the rising gear.

At frame S950,4WD controller 8 makes switch sign SLCFLG set (SLCFLG=1).After the switch S LCFLG set, be immediately in frame S340 with vehicle velocity V _CarMake comparisons and the threshold value speed of a motor vehicle of the 10km/h of raising is set.

Comprise that in execution this switch sign SLCFLG is reset in frame S1010 during the process based on slip of frame S370, S380 and S390.

According to embodiment, when coefficient of friction μ is low, if in vehicle velocity V _CarNot from the first speed rising gear, the threshold value speed of a motor vehicle of the 10km/h of raising is set when being less than or equal to the threshold value speed of a motor vehicle α of 5km/h.

In the embodiment shown in fig. 11, monitoring road surface coefficient of friction μ, shifting of transmission position and vehicle velocity V _CarTo determine whether the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.Feedforward 4WD control response first or apply driving torque to

rear wheel

3L and 3R based on the expectation value T Δ V of moment of torsion, this expectation value T Δ V is the power requirement determined (seeing Figure 11 center S350 and S360) that responds the driver.Feed back 2/4WD control response second or apply driving torque to

rear wheel

3L and 3R based on the expectation value T Δ V that slides, this expectation value T Δ V is that slide determined (seeing Figure 11 center S370, S380 and S390) quickened in response.

Flowcharting among Figure 12 is used to according to the present invention to control and starts and the service condition of another embodiment of the system of the accelerator of automobile or method subsequently.This embodiment is except providing new frame S1230 with the frame S340 in the alternate figures 6 in Figure 12, and is identical with the embodiment that at first discusses basically.In Fig. 6 and Figure 12, identical frame adopts identical reference number.

In Figure 12, at frame S1230,4WD controller 8 determines whether that by APO is compared with for example predetermined value zero the driver has power requirement.If APO, determines that the driver has power requirement greater than predetermined value.If driver's power requirement exists, logic from frame S1230 turn to comprise frame S350 and S360 based on the moment of torsion process.If driver's power requirement is always zero, logic steering comprises the upwards frame S440 of count cycle of frame S449 and S450.

According to this embodiment, work as vehicle velocity V _CarWhen being less than or equal to 5km/h threshold value speed of a motor vehicle α, if road surface coefficient of friction μ is lower, the response driver keeps feedforward 4WD control to the requirement of power.Then, if during predetermined 10 seconds, do not have the requirement of driver continuously to power, should be from feedforward 4WD control break to feedback 2/4WD control.

In this embodiment, monitoring road surface coefficient of friction μ and driver's power requirement is to determine whether the driving situation should be from feedforward 4WD control break to feedback 2/4WD control.Feedforward 4WD control response first or apply driving torque to

rear wheel

3L and 3R based on the expectation value T Δ V of moment of torsion, this expectation value T Δ V is the power requirement determined (seeing Figure 12 center S350 and S360) that responds the driver.Feed back 2/4WD control response second or apply driving torque to

rear wheel

3L and 3R based on the expectation value T Δ V that slides, this expectation value T Δ V is that slide determined (seeing Figure 12 center S370, S380 and S390) quickened in response.When change-speed box rising gear descended the driving torque that is applied to

rear wheel

In each embodiment, C1 applies moment of torsion to

rear wheel

3L and 3R by the order of response electrical generator, and automobile is driven with full wheel drive pattern, and this electrical generator order C1 is used as the input of the voltage regulator 22 of electrical generator 7.Voltage regulator 22 is adjusted to the indicated numerical value by electrical generator order C1 with magnetic field electric current of generator Ith.4WD controller 8 produces order C1.Response command C1, voltage regulator 22 is adjusted magnetic field electric current of generator Ifh, makes electrical generator 7 outputs at the determined voltage V of Fig. 8 center S650.The function that generator voltage V can be used as load torque Th is determined, and determines as the preceding description relevant with diagram of circuit Fig. 6 that do.Therefore, in automobile,, can adjust the driving torque that is applied to

wheel

3L and 3R by order C1 is controlled.

The present invention can be applied in the various automobiles with different types and design-calculated 4WD system.

When the present invention is specifically stated with reference to exemplary case, should be expressly understood that those know those skilled in the art person can be according to this paper to variously substituting of making of the technology statement of invention, modification and modification.Therefore above-mentioned variously substitute, modification and modification all do not break away from the defined scope and spirit of the present invention of appended claims.

It number be the rights and interests of the theme in the patent application of 2002-130257 that the application requires the Japanese publication submitted on May 2nd, 2002, and in this disclosure jointly as a reference.

Claims

1. a method that is used for the startup of Control of Automobile and accelerator subsequently is to apply moment of torsion by response command to wheel, and with full wheel drive mode activated automobile, this method comprises:

Starting and subsequently during the accelerator of automobile, ever-increasing predetermined variable and threshold value are being compared;

2. the method shown in claim 1, wherein predetermined variable is that the speed of a motor vehicle and wherein driving situation are determined by the monitoring road surface coefficient of friction and the speed of a motor vehicle.

3. require the method shown in 1 as profit, wherein predetermined variable is that the speed of a motor vehicle and wherein driving situation are determined by monitoring road surface coefficient of friction and transmitting ratio.

4. require the method shown in 1 as profit, wherein predetermined variable is that the speed of a motor vehicle and wherein driving situation are determined by monitoring threshold coefficient of friction, transmitting ratio and the speed of a motor vehicle.

5. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle, wherein driving situation be by monitoring road surface coefficient of friction and driver to power require determined.

6. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle and wherein sets up the threshold value speed of a motor vehicle that descends and improve with the road surface coefficient of friction, and need compare to determine whether the driving situation should change the speed of a motor vehicle and the threshold value of the being set up speed of a motor vehicle.

7. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle and wherein need determines that transmitting ratio has improved gear when the road surface coefficient of friction is low, to determine that the driving situation should change.

8. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle, wherein in case determine when the road surface coefficient of friction hangs down the transmitting ratio gear that also do not raise, just set up the threshold value speed of a motor vehicle that improves, and the speed of a motor vehicle and the threshold value speed of a motor vehicle of being set up are compared to determine whether the driving situation should change.

9. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle and wherein, when the road surface coefficient of friction is low, during predetermined, keep the speed of a motor vehicle to be higher than threshold value, determining that the driving situation should change, with this remain on predetermined during first expectation value of response moment of torsion determine order.

10. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle and wherein, when the road surface coefficient of friction is low, needs the requirement of driver to power, to determine that the driving situation should not change, determines order with this first expectation value that keeps responding moment of torsion.

11. require the method shown in 1 as profit, wherein predetermined variable is the speed of a motor vehicle and wherein, when the road surface coefficient of friction is low, need the requirement of driver to power, determining that the driving situation should not change, determine order and wherein with this first expectation value that keeps responding moment of torsion, when the road surface coefficient of friction is low, need not have the requirement of driver continuously in the scheduled period, determine that the driving situation should change, determine order with this first expectation value that remains on scheduled period response moment of torsion to power.

12. method as claimed in claim 6, wherein calculating quickens to slide provides the road surface coefficient of friction.

13. a system that is used for the startup of Control of Automobile and accelerator subsequently, automobile has to be equipped with and is used for by apply first power system of the driving engine that moment of torsion drives automobile to wheel, and system comprises:

Second power system with electrical motor is used for automobile being driven to the full wheel drive pattern that other wheel applies moment of torsion by response command; With

Controller, its operation can

Starting and subsequently during the accelerator of automobile, ever-increasing variable and threshold value are being compared;

When predetermined variable was less than or equal to threshold value, first expectation value of response moment of torsion was determined order;

Determine whether the driving situation should determine that order changes to the definite order of second expectation value of response moment of torsion from first expectation value of response moment of torsion; With

Apply order to power system.

14. system as claimed in claim 13, wherein second power system is included as the electric power source that electrical motor provides energy.

15. system as claimed in claim 14, wherein electric power source comprises with driving engine and can operate the electrical generator that connects.

16. system as claimed in claim 15, wherein second power system comprises the voltage regulator that electrical generator is required and the field current of voltage regulator response command regulator generator wherein.

17. a system that is used for the startup of Control of Automobile and accelerator subsequently, automobile has to be equipped with and is used for by apply first power system of the driving engine that moment of torsion drives automobile to first group of wheel, and system comprises:

With second power system that second group of wheel drive connects, use by response command automobile to be driven to the 4WD pattern that second group of wheel applies moment of torsion; With

Be used to produce the control device of order,

Wherein

Control device is starting and subsequently during the accelerator of automobile, ever-increasing variable and threshold value is being compared;

Control device response driver requires to determine first expectation value of moment of torsion;

Second expectation value that moment of torsion is determined in slip is quickened in the control device response;

When predetermined variable was less than or equal to threshold value, control device was determined order by first expectation value of response moment of torsion, carried out feedforward 4WD control;

Control device is determined order by second expectation value of response moment of torsion, determines whether the driving situation should be from carrying out feedforward 4WD control break to carrying out feedback 2/4WD control; With

Control device applies order to second power system.

18. system as claimed in claim 17, wherein second power system comprises electrical motor, and this electrical motor is as the source of torque to second group of wheel output torque.

19. a system that is used for the startup of Control of Automobile and accelerator subsequently uses by response command to the full wheel drive pattern that wheel applies moment of torsion automobile to be driven, system comprises:

Controller based on microprocessor;

The operation of controller can:

When predetermined variable is less than or equal to threshold value, determine order by first expectation value of response moment of torsion, carry out feedforward 4WD control; With

Second expectation value by the response moment of torsion is determined order, determines whether the driving situation should be from carrying out feedforward 4WD control break to carrying out feedback 2/4WD control.